时标上右端函数为两项和的集值微分方程解的平方收敛性

本文讨论了一类时标上右端函数为两项和的集值微分方程解的收敛性问题.首先引入时标上集值函数的Hukuhara导数意义下的Δ偏导数概念,并给出了时标上集值微分系统的比较原理.对于所构造的迭代序列,通过利用广义拟线性化方法和分析技巧,得到了上述问题近似解的平方收敛结果.     

一类激励时滞神经模型解的收敛性

本文考虑一类具时滞激励型神经网络模型,对初始函数和激励常数的一些不同取值范围,得到了其相应解的收敛性.     

时标上一类具有反馈控制的人口模型周期解的存在性与唯一性

由于时标理论不仅能够统一连续和离散分析,而且也具有重要的应用价值,因此主要研究时标上一类具有反馈控制的人口模型.利用Krssnoselskii不动点定理,得到了此人口模型周期解的存在性与唯一性.     

二元双阈值时滞神经网络模型解的渐近性

本文研究一类具时滞和非连续型信号函数的双阈值二元神经网络模型解的渐近性。在一定的初始函数空间内，对信号函数阈值的一些不同取值范围，证明了其解的收敛性，且明确给出了各平衡点的收敛域。     

时标上具非正中立项的二阶动力方程的动力学性质

研究时标T上的一类具非正中立项的非线性非自治二阶动力方程的动力学性质.利用时标上的有关理论,并结合一些经典不等式,得到了该方程的一些新的动力学性质,进一步推广和完善了动力方程的动力学性质.     

时标上具时滞积分-微分方程正解的存在性与稳定性（英文）

本文研究时标上一类具时滞积分-微分方程的正解的存在性与稳定性.运用Schauder不动点定理和时标上动力学方程分析理论,分别得到方程存在正δ_±移位周期解和正解的充分条件,及正解指数稳定的充分条件.最后,通过两个数值例子来说明结果的可行性.     

时标上一类三阶非线性中立型动力方程的振动性与渐近性

考虑了时标上一类三阶非线性中立型动力方程,得到了该方程一切解振动或渐近趋于零的充分条件.特别地,所得结果推广了一些已有的结论.     

自共轭椭圆型方程的样条解法

本文从二元样条空间的理论出发,构造了一类新的差分格式,并利用它得到了一类自共轭椭圆型方程的样条解,并证明了这样的解的唯一性和收敛性问题.最后,给出了一个数值例子,说明了本方法是可行的.     

时标上具有非线性谱参数边界条件的Sturm-Liouville问题的特征值（英文）

本文考虑一类时标上带有非线性多项式谱参数边界条件的Sturm-Liouville问题的特征值.结果表明特征值的个数不仅依赖于对时标的分割,而且依赖于多项式谱参数边界条件.     

时标上一类具阻尼项的二阶动态方程的振荡性

研究了时标上的一类具有阻尼项的二阶非线性中立型变时滞动态方程的振荡性,利用时标上的理论和广义的Riccati变换及不等式技巧,建立了该方程的几个新的振荡准则,这些准则不仅推广和改进了一些已知的结果,而且在时标上统一了具有阻尼项的二阶非线性时滞微分方程和差分方程的振荡性质.并给出了具体实例来说明文章的主要结论.     

Study of the blow-up of solutions of systems of equations of hydrodynamic type

Mathematical Notes - We study the initial boundary-value problem for three-dimensional systems of equations of pseudoparabolic type. The system is similar to the Oskolkov system, but differs from...     

Distribution of types of symmetry of tensors of high degree

The asymptotic distribution of tensors of degree N in symmetry types is studied in this paper.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 155, pp. 181–186, 1986.     

Characterization of types of asymptotic discernibility of families of hypotheses

We give a characterization of the types of asymptotic discernibility of families of hypotheses in the case of hypothetical measures that are not, in general, mutually absolutely continuous. The case when the logarithm of the likelihood ratio admits an asymptotic expansion of the type of an expansion with local asymptotic normality is examined in detail. Examples are studied.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 64–71, 1987.     

Axiomatizability of reducts of algebras of relations

In this paper, we prove that any subreduct of the class of representable relation algebras whose similarity type includes intersection, relation composition and converse is a non-finitely axiomatizable quasivariety and that its equational theory is not finitely based. We show the same result for subreducts of the class of representable cylindric algebras of dimension at least three whose similarity types include intersection and cylindrifications. A similar result is proved for subreducts of the class of representable sequential algebras. Received October 7, 1998; accepted in final form September 10, 1999.     

Lengths of periods of continued fractions of square roots of integers

Empirical study of the period’s length T of the continued fractions of $\sqrt{Q}$ (for growing integers Q) shows several strange asymptotical results, for instance, $T\leq C\sqrt{Q}\ln{Q}$ . These results show important differences between the statistics of the elements of the continued fractions of random real numbers and of square roots of random integers.